Automatic film-break detector for motion-picture machines



APPLICATION FILED OCT. I4, i915.

W. WENDERHOLD. AUTOMATIC FILM BREAK DETECTOR FoR Menon PICTURE MACHINES.

I APPLICATION FILED OCT. I4, I9l5. 1,358,806, Patented Nov. 16, 1920.

3 SHEETS-SHEET 2.

A TTUHNEY W. WENDERHOLD. AUTOMATIC FILM BREAK DETECTOR FOR MOTION PICTURE MACHINES.

l .APPLICATION FILED 0CT.14I i915. 1,358,806.

Patented Nov. 16, 1920.

3 SHEETS-SHEET 3.

/N VEN 70H W/ TNESSES:

A TTOR/IIEIl a UNITED STATES `PiiifEivT oFFicE.

wlmm WENDERHOLD, or NEW YORK, N. Y., ASSIGNOR To CRU PATENTS ConroaATIoN, A conPoRATIoN or NEW-Yoan.

AUToMATrc FILM-BREAK DETEcToaiFoR MOTIONTICTURE MACHINES.

l' 1o all 'whomvt may concern:

Be it known that I,

if the picture 4film therein has become broken or defective.

To accomplish the object of my invention,v

l provide a clutch mechanism between a driving shaft and the film-advancing device `and control the clutch mechanism by the body of `.the film itself, or by the tension applied to the-y'lilni.; lpreferably interpose the control membert of my device above ythe aperture lin a motion picture machine and as near the lupper reel as is permissible so that the control .device will stop7 `the motion picture machine operation ifi order that the `film may be quickly repaired as both of the defective ends of the film are in close proximity to each other above the aperture.

ln my of are the same. In the drawings the device is entirely controlled by the tension of the film. In the type shown 'in Fig. 1, the mere present of the film controls` the device.

Referrinr to the drawings, which form a part of tlus specification,

Figure 1 is a side elevationof a motion icture machine embodying one type of my invention.

Fig. 2 is a top view of a motion picture machine embodying another' type of my invention.

Fig. 3 isa side elevation of a motion picturernachine as referred to in 2. As shown in Fig. 1, the film is received from the usual, film reel 1, which is mounted on shaft 2, said shaft having afriction disk 3 and said friction disk receiving friction -by means O fa screw`4'. Members 1, 2, 3

and 4 are mounted on the frame support 5 and attached by screws 6 to the motion pic# ture machine 7; The film ,F passes by the .rollers 8 and 9, which are mounted fixedly.

The roller 10v is supported by an arm piv Specification of Letters Patent.`

FVILLIAMy WENDER- y HOLD, a citizen of the United States, res1du drawings illustrate two different types of my invention, but the objects there-v liatented N ov. 16, 1920.

Application led October 14, 1915,. Serial No. 55,794.

otally connected, said varm having a bevel gear 12. rlhetbevel gear 13is fastened on shaft 14, and is lmounted in the frame 7 at the points 7i* and a lever 15 with an engagp ing clutch pin 16 is mounted on the shaft 14. The clutch pin 16 engages the clutch controlling the connections between the crank shaft 17 and the main driving gear f 18. On the lower en d off shaft 14 is mounted another clutch lever 19 which carries the pin 20, the member controlling the connec- ,tionsbetween a motor driven shaft 20 and the general motion picture machine.

Should the film break at any time or the supply of film from reel lfail for any reason whatsoever,then the roiler 1f) on lever 11 will be forced in between the rollersfand 9 bythe pressure of the spring 21 and by the move-v ment of arm 11 the clutch of the crank sha-ft 17 and the motor shaft 20 will be dis'- engaged and the entire` motion ypicture machine film feeding mechanism will come to a pressed against the gear 18, which is mounted loosely yon a shaft 17, and when the lever 23 is operated, the action of the device, in

so far as described, is controlled merely by` the presence of film between the rollers 8, 9

land 10. No particular care need be taken regarding the tension on reel 1. ln fact, no tension is needed since the space between the rollers 8 and 9 is just sufficient to allow the `roller19--to pass between them.

In F igs. 2 and, the object of the device is the same, but the form it takes iS diderent and it is entirely controlled by the backward pull of the film F Ywhich is caused by the friction members 2, 3, 4 and 5 in Fi .11.

The upper film feed sprocket 24 is flexlbly mounted on the shaft 25 which carries gear 26, driven by .gear 18. n one end of shaft 25 a spring 27 is fastened to a collar 28. At. the other end of the spring lthe filmffeed sprocket 24 is connected at point 29.

therefore have a flexible driving connection tatable collar 30 and mounted in said pro`ecshaft 25 'and' the film tion is a pin 31, which connects the lm sprocket 24 with the rotatable collarl 30 by means of a spiral roove 32. If 'for any reason whatever the lm supply to the sprocket 24 should cease, then the spiral spring 27 will force the sprocket farther ahead than the natural rotation of shaft 25, and by means of the pin 31 in groove 32, the collar 30 is forced away from the sprocket 24, thus the lever 23 by means of pin 33 is moved on its pivotal axis 34, and through pinI 35 in lever 23a separates the clutch ,members 36 and 18. The clutch 36 is mounted on the crank shaft 17 said clutch being operatively connected with said crank shaft by key and slot 37. The pin engaging the gear on the lower end of shaft 34 is mounted on another lever 39, see'Fig. 3, and similar clutch'means on the motor driven shaft 40 as heretofore described on shaft 19. (See members 35, 36, 37 and 38.) The fiexible rotary movement of sprocket 24 is of course predeterminately limited either by slot 32 or by a pin 47, as indicated by the dotted lines in Fig. 3. The belt X is supposed to connect with a source of rotary power and same should apply to shaft 20 in Fig. 1. The rollers 41, 42 and 43 are the usual idler rollers used in motion picture machines, Suih asithe power projector. rl`he sprocket 24 is the usual continuously'rotating feed sprocket and 44 is the usual intermittently moved sprocket, and 45 is the usual lower take-up sprocket. On the sprocket 24 I provide a knurled knob 46 which is a part of said sprocket. The purpose of this knob Vis to give the operator means to set the mechanismin motion, as tension in the film F may not be present at the time it is desired to start the operation of the motion picture machine. Therefore, if the operator will turn the knob backward as indicated by arrowA 46a/in Fig. 3, the clutch members will be engaged independent of the action of the film while the operator is retarding the knob 46. e

The device can/be changed considerably without departing from the principles involved, and it may be stated that as shown in Fig. 1, the mechanism can be started by simply returning the roller 10v to the position illustrated in Fig. `1`.

The scope of my invention will be pointed out in the following claims.

I claim as my invention: y,

1. In a motion picture machine, the combination with a driving shaft for operating the same, of a film advancing device, a clutch for establisliin mechanical connection between said sha t and device, and means controlled by the tension of the film passing throughthe machine for maintaining said clutch in engagement with said shaft to transmit rotary motion therefrom to said device.

tension on the film becomes less than the predetermined degree. I

3. In a motion picture machine, a driving shaft for operating the same, a film feed sproket, connections between said shaft and sprocket, a roll of film, a pivotally mounted roller positioned to bear against the film to be influenced by variations in thek tension thereof, and means controlled bythe pivotal movement of said roller for controlling the connef tions between said shaft and sprocket.

4. In a motion picture machine, a driving shaft, a film feed sprocket, connections between said shaft and said sprocket, a clutch for controlling said connections, and means controlled by the tension of the film passing through the machine for controllingv said clutch. Y i

5. In a motion picture machine, a driving shaft, a film feed sprocket, connections between said shaft and said sprocket, a clutch for controlling said connections, al roll of film mounted in said machine, and means.

controlled by the tension of the film between the roll and said sprocket, for controlling said clutch.

6. In a motion picture machine, a shaft for operating the same, a film feed sprocket, connections between said shaft and said sprocket, a clutch for controlling said connections, means controlled by the tension of a film passing through said machine fornormally maintaining said clutch in engaging position to establish power connection between said shaft and said,sprocket, and- WILLIAM WENDERHOLD.

In presence of- RO'BERT RICHTER, FRED F. Weiss. 

